Iron Silicide Sputtering Target and Method for Production Thereof

ABSTRACT

An iron silicide sputtering target in which the oxygen as a gas component in the target is 1000 ppm or less and a method of manufacturing such an iron silicide sputtering target are provided. The method includes the steps of melting/casting high purity iron and silicon under high vacuum to prepare an alloy ingot, subjecting the ingot to gas atomization with inert gas to prepare fine powder, and thereafter sintering the fine powder. The amount of impurities in the target will be reduced, the thickness of a βFeSi 2  film during deposition can be made thick, the generation of particles will be reduced, a uniform and homogenous film composition can be yielded, and the sputtering characteristics will be favorable. The foregoing manufacturing method is able to stably produce the target.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No. 10/527,320which is the National Stage of International Application No.PCT/JP03/11152, filed Sep. 1, 2003, which claims the benefit under 35USC §119 of Japanese Application No. 2002-265447, filed Sep. 11, 2002.

BACKGROUND OF THE INVENTION

The present invention relates to an iron silicide sputtering targethaving transition-type semiconductor characteristics and suitable forforming a βFeSi₂ thin film to be used as an optical communicationelement or solar battery material, and the manufacturing method of suchiron silicide sputtering target.

Although silicon has been the most popular material conventionally as aLSI semiconductor material, a compound semiconductor ofindium/phosphorus, gallium/arsenic or the like is being used for opticalcommunication (LE/LED).

Nevertheless, indium has an extremely short life span as a resource, andit is said that it can only be mined for another 20 years or so.Further, arsenic is well known as an element having strong toxicity.Thus, there is no choice but to say that the optical communicationsemiconductor materials being widely used today have significantproblems for use.

In particular, the semiconductor element of gallium/arsenic being usedin cell phones with a short product-life cycle includes arsenic havingstrong toxicity, and this is causing a significant problem regarding thewaste disposal thereof.

Under the foregoing circumstances, it has been discovered that βFeSi₂possesses transition-type semiconductor characteristics, and is beingnoted as a favorable optical communication element and solar batterymaterial. The greatest advantage of this βFeSi₂ is that the respectiveconstituent elements are extremely abundant on earth, and that there isno danger of toxicity or the like. Thus, these materials are known asenvironmentally friendly materials.

Nevertheless, this βFeSi₂ is not free of problems, and, at present,technology for preparing high-quality material comparable to compoundsemiconductors of indium/phosphorus, gallium/arsenic or the like has notyet been established.

Currently, as technology for forming an FeSi₂ thin film, proposed istechnology for forming βFeSi₂ by sputtering an Fe target and forming anFe film on a Si substrate, and thereafter generating a silicideformation reaction between Si as the substrate material and the Fe filmby heating the deposited Si substrate.

Nevertheless, there are problems in that, with this method, since thesubstrate needs to be heated at a high temperature for a long periodduring deposition and during annealing, there will be limitations on thedevice design, and that it is difficult to form a thick βFeSi₂ filmsince the silicide formation reaction is based on the diffusion of Sifrom the substrate.

As a method similar to the above, proposed is a method of accumulatingFe on the Si substrate while maintaining the substrate at a temperaturein which Fe and Si will react; that is, at 470° C., but this method alsoencounters problems similar to those described above.

Further, as another method, proposed is a method for forming a βFeSi₂film by separately sputtering the Fe target and Si target; that is,performing co-sputtering so as to laminate several layers of the Felayer and Si layer, and heating this to generate a silicide formationreaction.

Nevertheless, with this method, there are problems in that thesputtering process will become complex, and that it is difficult tocontrol the uniformity of the thickness direction of the film.

Each of the foregoing methods is based on the premise of performingannealing after depositing Fe on the Si substrate, and, with thesemethods that require heating at high temperatures for a long period, aproblem has been noted in that the βFeSi₂, which was formed in a filmshape, becomes aggregated into an island shape together with theprogress of annealing.

Further, with the foregoing methods, since the Fe target is aferromagnetic body, it is difficult to perform magnetron sputtering, andit is thereby difficult to form an even film on a large substrate.Therefore, an even βFeSi₂ film with few variations in the compositionresulting from the subsequent silicide formation could not be obtained.

Moreover, although a proposal of a target (mosaic target) in which Feand Si blocks are disposed in a prescribed area ratio has also beenmade, since the sputtering rate of Fe or Si, whichever is sputtered,will differ considerably, it is difficult to deposit a prescribed filmcomposition on a large substrate, and it was not possible to prevent thearcing or generation of particles at the bonding interface of Fe and Si.

Conventionally, as technology employing FeSi₂, technology relating tothe manufacturing method of a thermoelectric material including thesteps of forming capsule particles by covering the nuclear particles ofFeSi particles with Si particles of a prescribed weight ratio,performing current-conduction sintering to the powder aggregate of thecapsule particles, and generating an FeSi₂ intermetallic compound hasbeen disclosed (e.g., refer to Japanese Patent Laid-Open Publication No.H5-283751).

Further, a manufacturing method of βFeSi₂ including a step ofpulverizing and mixing raw material powder containing Fe powder and Sipowder, a step of molding the pulverized and mixed powder, and a step ofsintering the molded material has been disclosed (e.g., refer toJapanese Patent Laid-Open Publication No. H6-81076).

Moreover, a manufacturing method of iron suicide thermoelectric materialincluding the steps of mixing ferrosilicon and iron powder, andsubsequently performing pressure sintering thereto at a sinteringtemperature of 900 to 1100° C. under an inert atmosphere has beendisclosed (e.g., refer to Japanese Patent Laid-Open Publication No.H7-162041).

Further, a manufacturing method of raw material powder for an FeSi₂thermoelectric conversion element including the steps of mixing aprescribed amount of transition metal powder to fine powder obtained viajet mill pulverization with inert gas so as to easily obtain fine powderhaving a low residual oxygen content and an average grain size ofseveral μm or less, performing spray granulation thereto with a spraydryer, and subsequently performing pressing and sintering thereto hasbeen disclosed (e.g., refer to Japanese Patent Laid-Open Publication No.H10-12933).

Moreover, a metallic silicide luminescent material in which a β-ironsilicide semiconductor element, which is a metallic silicidesemiconductor particle having a grain size on the order of nanometers,is dispersed in a particle shape in the polycrystalline silicon has beendisclosed (e.g., refer to Japanese Patent Laid-Open Publication No.2000-160157).

SUMMARY OF THE INVENTION

The present invention was devised in order to overcome the foregoingproblems, and an object thereof is to provide an iron silicidesputtering target in which the amount of impurities will be reduced, thethickness of the βFeSi₂ film during deposition can be made thick, thegeneration of particles will be reduced, a uniform and homogenous filmcomposition can be yielded, and the sputtering characteristics will befavorable, as well as the method of stably manufacturing such an ironsilicide sputtering target.

The present invention provides an iron silicide sputtering target,wherein the content of oxygen as a gas component in the target is 1000ppm or less, 600 ppm or less or 150 ppm or less. The iron silicidesputtering target can have a content of carbon as a gas component of 50ppm or less, a content of nitrogen as a gas component of 50 ppm or less,a content of hydrogen as a gas component of 50 ppm or less, and acontent of sulfur as a gas component of 50 ppm or less. The ironsilicide sputtering target can have a relative density of 90% or more or95% or more. The iron silicide sputtering target can have an averagecrystal grain size of a target texture of 300 μm or less, 150 μm orless, or 75 μm or less. The target texture of the iron silicidesputtering target is substantially a ζ_(a) phase, or the primary phaseis ζ_(a) phase.

The present invention also provides a method of manufacturing an ironsilicide sputtering target, including the steps of melting/casting highpurity iron and silicon under high vacuum to prepare an alloy ingot,subjecting the ingot to gas atomization with inert gas to prepare finepowder, and thereafter sintering the fine powder. The high purity ironand silicon can be melted with a cold crucible melting method employinga water-cooled copper crucible. The fine powder can be sintered via hotpressing, hot isostatic pressing or spark plasma sintering. The finepowder can be heated under a hydrogen atmosphere and subject todecarbonization/deoxidization processing, subject to degasificationprocessing under a vacuum atmosphere, and thereafter sintered.

DETAILED DESCRIPTION OF THE INVENTION

Although the iron silicide sputtering target of the present invention isrepresented with the molecular formula of FeSi₂ unless otherwisespecified, this includes the scope of FeSi_(x) (x: 1.5 to 2.5).

Further, the iron silicide sputtering target used in this descriptionmeans every type of iron silicide comprising the property ofsemiconductors, and iron suicide containing iron silicide as its primarycomponent and small amounts of other additive elements, and the presentinvention covers all of the above.

With the iron silicide sputtering target of the present invention, thecontent of oxygen as the gas component is 1000 ppm or less, preferably600 ppm or less, and more preferably 150 ppm or less. As a result, thegeneration of particles during sputtering can be suppressed, and auniform and homogenous film composition can be yielded.

Further, from the perspective of similar characteristic, it is desirablethat the content of carbon as the gas component in the target is 50 ppmor less, the content of nitrogen as the gas component in the target is50 ppm or less, the content of hydrogen as the gas component in thetarget is 50 ppm or less, and the content of sulfur as the gas componentin the target is 50 ppm or less. Incidentally, a gas component means theelement detected in a gas state upon performing quantitative analysis.

Moreover, when the relative density of the target is 90% or more,preferably 95% or more, and the average crystal grain size of the targettexture is 300 or less, preferably 150 μm or less, and more preferably75 μm or less, arcing and generation of particles can be furthersuppressed, and a film having stable characteristics can be obtainedthereby.

When the iron silicide target texture is substantially a ζ_(a) phase, orthe primary phase is a ζ_(a) phase; that is, when the phasetransformation to the β phase (semiconductor phase) is suppressed andthe ζ_(a) phase still remains, a stable bias current can be applied tothe target, and plasma density can be increased easily, and thesputtering gas pressure can be kept low. As a result, a superior effectis yielded in that a favorable film with few gas damages can beobtained.

Upon manufacturing the iron silicide sputtering target of the presentinvention, high purity iron of 3N5 (99.95 wt %, hereinafter the same) ormore, preferably 4N or more, and more preferably 4N5 or more, andsilicon of 5N or more are used as the raw materials.

These are melted/cast under high vacuum to prepare an alloy ingot, theseare melted once again and then subject to gas atomization with inert gasto prepare fine powder, and this fine powder is sintered to form asintered body, and this is manufactured into a target to obtain the ironsilicide sputtering target.

Upon melting the high purity iron and silicon, it is desirable toperform this with the cold-crucible melting method employing a copperwater-cooled crucible. With this cold-crucible melting method, incomparison to the ordinarily adopted vacuum induction melting methodemploying an aluminum crucible, the oxidization of the raw materials andmixing of impurities from the crucible can be suppressed, and an ingothaving a uniform composition can be obtained.

When pulverizing the obtained ingot, in comparison to mechanicalpulverizing methods employing a stamp mill or ball mill, since theatomization method employing inert gas is able to rapidly cool, solidifyand pulverize the ingot, spherical fine powder with minimalcontamination (particularly oxidization) and favorable degree ofsintering can be obtained. According to the above, fine powder with ahigh residual ratio of ζ_(a) (also referred to as the aFe₂Si₅ phase oraFeSi₂ phase) (metallic phase) can be obtained.

The obtained fine powder is sintered via hot pressing, hot isostaticpressing or spark plasma sintering. Upon sintering, spark plasmasintering is particularly desirable. According to this spark plasmasintering method, the growth of crystal grains can be suppressed, and ahigh density, high strength target can be sintered. Further, sincesintering can be performed in a short period and this can be cooledrapidly, the phase transformation to the β phase (semiconductor phase)can be suppressed, and a target having a high residual ratio of ζ_(a)phase (metallic phase) can be obtained. If different phases exist in thetarget, the rate of sputtering will differ, and this is not preferablesince this will cause the generation of particles.

Predominately, when a single phase ζ_(a) phase (metallic phase) is used,a stable bias current can be applied to the target, plasma density canbe increased easily, and the sputtering gas pressure can be kept low.Thus, a favorable film with few gas damages can be obtained.

Further, prior to sintering, it is preferable to heat the fine powderunder a hydrogen atmosphere, perform decarbonization/deoxidizationprocessing thereto, and further perform degasification processingthereto under a vacuum atmosphere. As a result, it is possible to obtaina sputtering target in which the gas components can be eliminated, thegeneration of particles will be reduced, a uniform and homogenous filmcomposition can be yielded, and the sputtering characteristics will befavorable.

EXAMPLES AND COMPARATIVE EXAMPLES

The present invention is now explained in detail with reference to theExamples and Comparative Examples. These Examples are merelyillustrative, and the present invention shall in no way be limitedthereby. In other words, the present invention shall only be limited bythe scope of claim for a patent, and shall include the variousmodifications other than the Examples of this invention.

Examples 1 to 3

High purity Fe having a purity of 3N5 to 5N and high purity Si having apurity of 5N in block shapes were weighed at a prescribed molar ratio,these were melted at 1250 to 1600° C. with a cold-crucible melting unitemploying a water-cooled copper crucible (vacuuming was sufficientlyperformed until the ultimate vacuum prior to heating reached an order of10⁻⁵ ton), and then cast in a mold in a vacuum to prepare an ingot. Uponmelting, after foremost melting Fe, Si was gradually added to the Femolten metal and sufficiently alloyed. Moreover, these were also alloyedwith a vacuum induction melting unit employing a high purity aluminacrucible and an arc melting unit.

The ingot obtained pursuant to the above was melted once again, and thiswas atomized in argon gas (gauge pressure of 50 to 80 kgf/cm²) with agas atomization device to prepare spherical alloy powder having adiameter of 300 μm or less.

Powder of a prescribed grain size was sieved from such spherical alloypowder, and sintered for 2 hours in a vacuum atmosphere with hotpressing at 1000 to 1220° C. and a surface pressure of 250 to 300kgf/cm². The surface of the obtained sintered body was ground with aflat-surface grinding machine to remove the contamination layer on thesurface thereof, and an iron silicide target of φ300 mm×5 mm wasprepared thereby.

The raw material purity, composition (Fe:Si) ratio, dissolution method,pulverizing method, sieved grain size, and sintering method of Examples1 to 3 are respectively shown in Table 1.

TABLE 1 Raw Material Dissolution Pulverization Sieved Purity Fe:Si RatioMethod Method Grain Size Sintering Method Example 1  Fe(3N5) 1:2.2 ColdCrucible Ar Gas Atomtzation Ave. 30 μm HP Example 2  Fe(3N5) 1:1.8 VIMAr Gas Atomization Ave. 31 μm HP Example 3 Fe(4N) 1:2.5 Arc Melting ArGas Atomization Ave. 35 μm HP Example 4 Fe(4N) 1:2.2 Cold Crucible ArGas Atomization Ave. 33 μm HIP Example 5 Fe(5N) 1:2.0 Cold Crucible ArGas Atomization Ave. 18 μm HIP Example 6 Fe(4N) 1:1.8 Cold Crucible ArGas Atomization Ave. 35 μm SPS Example 7 Fe(5N) 1:1.5 Cold Crucible ArGas Atomization Ave. 28 μm SPS Example 8 Fe(4N) 1:2.05 Cold Crucible ArGas Atomization Ave. 45 μm HP (w/deoxidization and heat treatmentExample 9 Fe(5N) 1:2.5 Cold Crucible Ar Gas Atomization Ave. 120 μm HP(w/deoxidization and heat treatment) Example 10 Fe(5N) 1:2.01 ColdCrucible — — HIP Comparative  Fe(3N5) 1:1.6 VIM Ball Mill Ave. 10 μm HPExample 1 Comparative  Fe(3N5) 1:1.6 VIM Ball Mill Ave. 16 μm HP Example2 Comparative Fe(4N) 1:2.3 VIM Ar Gas Atomization Ave. 160 μm HIPExample 3 Comparative  Fe(3N5) 1:2.0 Arc Melting Ball Mill Ave. 12 μmHIP Example 4 Comparative Fe(4N) 1:2.0 Arc Melting Ball Mill Ave. 10 μmSPS Example 5 HP: Hot Pressing HIP: Hot Isostatic Pressing SPS: SparkPlasma Sintering VIM: Vacuum Induction Melting

Examples 4 and 5

Hot isostatic pressing was used as the sintering method. The otherconditions were the same as Examples 1 to 3.

As the specific conditions of hot isostatic pressing, the foregoingpowder was vacuum-encapsulated in a soft steel container, and sinteredfor 3 hours at 1150° C. at an atmospheric pressure of 1500. The surfaceof the obtained sintered body was ground with a flat-surface grindingmachine to remove the contamination layer on the surface thereof, and aniron silicide target of φ300 mm×5 mm was prepared thereby.

Details regarding the raw material purity, composition (Fe:Si) ratio,dissolution method, pulverizing method, sieved grain size, and sinteringmethod of Examples 4 and 5 are respectively shown in Table 1.

Examples 6 and 7

Spark plasma sintering was used as the sintering method. The otherconditions were the same as Examples 1 to 3. Details regarding the rawmaterial purity, composition (Fe:Si) ratio, dissolution method,pulverizing method, sieved grain size, and sintering method of Examples6 and 7 are respectively shown in Table 1.

As the specific conditions of spark plasma sintering, the raw materialpowder shown in Table 1 was filled inside a graphite mold and sinteredfor 5 minutes with a pulse current of 8000 A. As a result of employingthe spark plasma sintering method, high density plasma will be generatedat the contact site of the filled particles, and rapid sintering wasenabled.

The surface of the obtained sintered body was ground with a flat-surfacegrinding machine to remove the contamination layer on the surfacethereof, and an iron silicide target of φ125 mm×5 mm was preparedthereby.

Examples 8 and 9

In these Examples, other than the temporary sintered body being subjectto hydrogen processing→vacuum processing, the other conditions were thesame as Example 1 to 3. Details regarding the raw material purity,composition (Fe:Si) ratio, dissolution method, pulverizing method,sieved grain size, and sintering method of Examples 8 and 9 arerespectively shown in Table 1.

A temporary sintered body with a density of 70 to 90% and having openpores was prepared with hot pressing at a sintering temperature of 700to 1000° C., heat treatment was performed to this temporary sinteredbody in a hydrogen gas stream at 900° C. for 5 hours, decarbonizationand deoxidization processing was further performed thereto, anddegasification was subsequently performed via heat treatment in a vacuumatmosphere (order of 10⁻⁴ torr).

Next, this temporary sintered body was sintered with hot pressing. Thesurface of the obtained sintered body was ground with a flat-surfacegrinding machine to remove the contamination layer on the surfacethereof, and an iron silicide target of φ300 mm×5 mm was preparedthereby.

Example 10

This Examples does not use pulverized powder, and obtains a targetmaterial by slicing the vacuum-melted ingot, and subject this to heattreatment. The other conditions were the same as Examples 1 to 3.Details regarding the raw material purity, composition (Fe:Si) ratio,dissolution method, and sintering method of Example 10 are respectivelyshown in Table 1.

After preparing a cast ingot under the same conditions as Examples 1 to3, this ingot was cut with a wire saw, further subject to hot isostaticpressing at 1050° C. and an atmospheric pressure of 1500 so as to reducethe cast defects, and the surface of the obtained sintered body wasground with a flat-surface grinding machine as with the foregoingExamples to remove the contamination layer on the surface thereof, andan iron silicide target of φ150 mm×5 mm was prepared thereby.

Comparative Examples 1 to 3

High purity Fe having a purity of 3N5 to 5N and high purity Si having apurity of 5N in block shapes were weighed at a prescribed molar ratio,these were melted at 1250 to 1600° C. with a high purity aluminacrucible and vacuum induction melting unit. Upon melting, after foremostmelting Fe, Si was gradually added to the Fe molten metal andsufficiently alloyed.

After melting, this was cast in a mold in a vacuum to prepare an ingot.Next, the ingot was cut, roughly pulverized to be approximately 1 mm orless with a stamp mill, and then pulverized for 10 hours with a ballmill.

Upon pulverization, the cylindrical column (diameter of roughly 10 mm,length of 15 mm) of high purity Fe was filled up to ⅓ of the innervolume of the ball mill to become the grinding medium, and, afterplacing the roughly pulverized ingot therein, argon gas was substitutedwithin the mill to prevent oxidization.

Powder of a prescribed grain size was sieved from such spherical alloypowder, and sintered for 2 hours with hot pressing at 1000 to 1220° C.and a surface pressure of 250 to 300 kgf/cm².

The surface of the obtained sintered body was ground with a flat-surfacegrinding machine to remove the contamination layer on the surfacethereof, and an iron silicide target of φ300 mm×5 mm was preparedthereby.

The raw material purity, composition (Fe:Si) ratio, dissolution method,pulverizing method, sieved grain size, and sintering method ofComparative Examples 1 to 3 are respectively shown in Table 1.

Comparative Examples 4 and 5

Other than employing the arc melting method for preparing the ingot, thetarget was manufactured under the same conditions as ComparativeExamples 1 to 3.

The surface of the obtained sintered body was ground with a flat-surfacegrinding machine to remove the contamination layer on the surfacethereof, and an iron silicide target of φ300 mm×5 mm was preparedthereby. The raw material purity, composition (Fe:Si) ratio, dissolutionmethod, pulverizing method, sieved grain size, and sintering method ofComparative Examples 4 and 5 are respectively shown in Table 1.

The oxygen analysis results of the targets of Example 1 to 10, andComparative Examples 1 to 5 are shown in Table 2, and regarding Examples1, 5 and 10, the analysis results of other impurities are shown in Table3.

Further, texture of the target was observed at 17 locations radially,and the average crystal grain size was calculated with the sectionmethod from the texture photograph. Moreover, the density was measuredwith the Archimedes method, and the crystal structure was furtherexamined with XRD. The results are shown in Table 2.

In addition, the targets of Example 1 to 10, and Comparative Example 1to 5 were used to perform DC magnetron sputtering on a 3-inch Si (100)substrate so as to evaluate the sputtering characteristics and filmcharacteristics of the target. The results are similarly shown in Table2.

TABLE 2 Oxygen Relative Average Uniformity Particles (ppm) Density (%)Grain Size (3σ) Quantity/cm² Example 1 820 92.5 112 μm 4.2% 0.3 Example2 680 95.5 150 μm 1.6% 0.5 Example 3 450 96 180 μm 2.3% 1.2 Example 4420 97 123 μm 1.9% 2.5 Example 5 460 93 42 μm 3.1% 0.9 Example 6 110 9296 μm 1.8% 0.5 Example 7 140 97.5 52 μm 3.4% 0.5 Example 8 350 95.3 65μm 1.8% 2.3 Example 9 24 96.5 290 μm 3.2% 1.6 Example 10 40 100 560 μm12.5% 0.6 Comparative 2300 96 52 μm 3.0% 7.8 Example 1 Comparative 180096 260 μm 2.8% 25.1 Example 2 Comparative 1200 88 36 μm 28.6% 36.3Example 3 Comparative 1500 98 40 μm 1.5% 13.3 Example 4 Comparative 160097 85 μm 0.8% 10.2 Example 5

TABLE 3 Unit: ppm Example 1 Example 4 Example 10 C 26 13 4 N 18 8 1 H 159 2 S 1 5 1 P 5 <1 1 Cl 59 <1 <1 Mn 6 <0.1 0.2 Cu 8 <1 0.3 Al 3 <0.5 0.3As <1 <1 <1 B 0.5 <1 <1 Bi <1 <1 <1 Ca <2 <1 <1 Cd <0.1 <1 <1 Co 16 15 1Cr <0.5 <0.3 0.3 Mg <0.1 <1 <1 Mo <0.2 <1 <1 Pb 0.5 <1 0.2 Sb 0.5 <1 <1Sn 0.3 <1 <1 Ti <0.1 <1 <1 V <0.4 <1 <1 W 0.3 <1 <1 Zn 1.2 <0.4 <1 Zr <1<1 <1 Te <1 <1 <1 Ag <1 <1 <1 Na <1 <1 <1 K <1 <1 <1 U <0.005 <0.005<0.005 Th <0.005 <0.005 <0.005

As shown in Table 2, in the Examples of the present invention, theoxygen content as impurity was low, the relative density was 90% ormore, the average crystal grain size was 300 μm or less (excluding themelted target of Example 10), the area ratio of ζ_(a) was 70% or more,the evenness (uniformity, 3σ) of the film was favorable, the generationof particles was significantly reduced, and the sputteringcharacteristics were favorable. Further, as shown in FIG. 3, otherimpurities were also significantly reduced.

Meanwhile, in each of the Comparative Examples, the oxygen content washigh, the ratio of βFeSi₂ was also high, and the target showedsignificant generation of particles, and a film that could be peeledeasily was formed. These problems caused the deterioration of thesputtered deposition quality. Moreover, the peak of βFeSi₂ from the XRDmeasurement could not be observed from either the Example or ComparativeExamples.

The iron silicide sputtering target of the present invention yields asuperior effect in that the amount of impurities such as oxygen will bereduced, the thickness of the βFeSi₂ film during deposition can be madethick, the generation of particles will be reduced, a uniform andhomogenous film composition can be yielded, and the sputteringcharacteristics will be favorable. The present invention also yields asuperior effect in that such target can be stably manufactured.

1. A method of manufacturing an iron silicide sputtering target,comprising the steps of melting and casting high purity iron and siliconunder high vacuum to prepare an alloy ingot, subjecting the ingot to gasatomization with inert gas to prepare fine powder, and thereaftersintering the fine powder to provide an iron silicide sputtering targetsuch that the iron silicide sputtering target has a content of oxygen asa gas component of 1000 ppm or less, a relative density of at least 90%,and a target texture with an average crystal grain size of 300 μm orless, said target texture being substantially a ζ_(a) phase, or having aprimary phase that is a ζ_(a) phase.
 2. A method according to claim 1,wherein the high purity iron and silicon are melted with a cold cruciblemelting process employing a water-cooled copper crucible.
 3. A methodaccording to claim 2, wherein the fine powder is sintered by one of hotpressing, hot isostatic pressing, and spark plasma sintering.
 4. Amethod according to claim 3, wherein, before said sintering step, thefine powder is heated under a hydrogen atmosphere, subjected todecarbonization and deoxidization processing, and subjected todegasification processing under a vacuum atmosphere.
 5. A methodaccording to claim 1, wherein the fine powder is sintered by one of hotpressing, hot isostatic pressing, and spark plasma sintering.
 6. Amethod according to claim 1, wherein, before said sintering step, thefine powder is heated under a hydrogen atmosphere, subjected todecarbonization and deoxidization processing, and subjected todegasification processing under a vacuum atmosphere.